Geotextiles are permeable fabrics that are used in soil to improve its characteristics. They make poor soil more manageable, enabling construction in places that would otherwise be unsuitable. Typically made from polypropylene or polyester, geotextiles are ideal materials for many infrastructure works, such as roads, harbors, landfills, drainage structures, and other civil projects. Geotextile helps in maintaining the integrity of the pavement structure through the functions of separation, filtration, transmissivity and reinforcement. There are two main types of geotextile: permeable and impermeable Permeable membranes can be split into two categories again: woven and non-woven (or fibre).
Non-woven geotextiles are manufactured by a thermal bonding process of orientated filaments, either randomly or directionally and it provides porous separation between different layers in the ground, such as surface to sub-base or sub-base to sub-grade. They also offer great filtration properties to allow water to drain naturally into the ground.
Woven products are manufactured by the interlacing of two or more sets of yarn, fibre, filaments or similar. They are designed to offer reliable ground stabilisation and weed prevention capabilities. Woven geotextile membranes boast high tensile strengths and this makes them ideal for road construction and plant applications.
Water rises up into the base course and leads to saturation which alters the vertical stress distribution of oncoming loads directly to subgrade soil thus neutralising the benefits of the structural layers. Therefore, to achieve soil stabilization, elimination of saturation in the base course is a right objective. Geotextile products works as a capillary break and thus prevents the rise of ground water and achieve soil stabilization
The ability of geotextiles to allow continuous liquid flow through its layer while preventing migration of fine soil particles across the layer and hence provides a permanent solution for lowering the ground water table. Geotextile by virtue of their transmissivity function also serve as a scour protection layer and increase the life and performance of the canals.
Reflective cracking is a major problem associated with asphalt concrete pavements and the stress absorption capabilities of the fabric layer helps in eliminating this problem.
Using a Geotextile, acting primarily as a separation layer, the migration of soil into the ballast is prevented and the integrity and functioning qualities of the ballast are maintained, enabling safer and faster train travel.
ROAD AND RUNWAY
Geotextile distribute the pavement loads and offer effective construction over weak surfaces and shallow water areas. Pavement life is also enhanced by the use of a geotextile.